Chassis, radiator removal, wheelie bar, etc. There's some pretty visible places in that picture. All of those and more were addressed on the new setup.
The shifting and the plugs backing out might be related but are separate issues. You MUST get the detonation under control before it pukes the motor. If its setup for race then run race. If you don't want spendy fuel then have a set of domes cut for pump fuel. AFTER you can make passes without backing the plugs out then you can address your shifting issues.
Good luck. Guys that are REALLY concerned about weight are pretty tight lipped about it. I will say you will need to think outside the boxa far as materials go if you are going to get to the weights of the top contenders.